You could also hold onto it for a couple of days until the papers are served and see if there is going to be some huge backlash. if there isnt then spend it on your daughter. if there is then send it back.
But I dont see anything morally wrong with taking it and it wont make you look bad in court - in fact it should never come up in court as she isnt party to it. if it did then it would make him look bad that his Mommy had to help because he wouldnt.